Synthesis and testing of a p-H2 hyperpolarized 13C probe based on the pyrazolo[1,5-a]pyrimidineacetamide DPA-713, an MRI vector to target the peripheral benzodiazepine receptors.
Magn Reson Chem
; 49(12): 795-800, 2011 Dec.
Article
en En
| MEDLINE
| ID: mdl-22095873
ABSTRACT
DPA-713 is the lead compound of a recently developed 2-phenylpyrazolo[1,5-a]pyrimidineacetamide series that has been shown to display a good targeting capability toward peripheral benzodiazepine receptors, recently renamed translocator protein (18 kDa) or in short TSPO. On the basis of this structure, a novel derivative bearing a [(13)C]butynoate moiety has been designed and synthesized (three steps-42% overall yield) providing, upon rapid and quantitative para-hydrogenation, the corresponding hyperpolarized [(13)C]alkene. Para-hydrogen-induced polarization effects have been detected in both (1)H and (13)C-NMR spectra. Upon applying a field cycling procedure, the spin order of para-H(2) added hydrogens is transferred on the (13)C carboxylate moiety yielding a signal enhancement of approximately 4500 times. T(1) of the carboxylate carbon atom is approximately 21.9 s (at 9.37 T). A (13)C-MR image has been acquired by using the (13)C RARE (Rapid Acquisition by Relaxation Enhancement) acquisition protocol on a 10-mM solution. The main limitation to the in vivo use of this novel para-hydrogenated [(13)C]derivative is its relatively low solubility in aqueous systems.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Pirazoles
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Pirimidinas
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Isótopos de Carbono
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Imagen por Resonancia Magnética
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Receptores de GABA
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Ésteres
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Antagonistas de Receptores de GABA-A
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Hidrógeno
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Marcaje Isotópico
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Acetamidas
Límite:
Humans
Idioma:
En
Revista:
Magn Reson Chem
Asunto de la revista:
QUIMICA
Año:
2011
Tipo del documento:
Article
País de afiliación:
Italia